Compared with body fluid assessment and body composition analysis methods such as isotope dilution method and underwater weighing, multi-frequency body composition analyzer-Bodystat 1500MDD provides a fast, simple, economical and non-invasive method to evaluate body fluid content and perform body composition analysis. analyze. The principle of measuring the conduction of electrical current through the body (impedance) is based on the chosen frequency. At low frequencies, the current cannot pass through the cell surface, so it is mainly conducted through the extracellular fluid. At high frequencies, the current can break through the cell membrane and be co-conducted through the extracellular fluid (ECW) and intracellular fluid (ICW). By measuring the impedance at 5kHz and 50kHz and applying the prediction equation, we can evaluate the extracellular fluid (ECW) and the total fluid (TBW) indicators separately, and then calculate the intracellular fluid (ICW) indicator by subtraction. ECW correlates with extracellular mass and ICW correlates with somatic mass. Body fat, muscle mass and dehydrated muscle mass can be assessed by measuring impedance at 50kHz and applying the unique Bodystat algorithm.